DayStar is proud to offer the only Helium D3 Solar Filter available on the market today. Due to our recent advancements in technology which allow more precise tuning of a DayStar filter, we are finally able to capture the Helium emission line.
Discovered in the visual spectrum at 5875.61Å nearby Sodium D1 and D2 lines by Pierre Janssen in 1868 during a solar eclipse, Helium is the second most abundant element in the Universe.
Research studies in D3 in the past have focused on flare research and comparisons of correspondence of absorption in D3 with Magnetic Lines. Those studies used 'overlapograms', as He D3 filters have not been available before today.
Features visible in D3 are: Sunspot Detail, SuperGranulation, Plague, Emission in Flare Footprints, Absorption following Magnetic Lines and small prominences.
See below for photos and descriptions of features visible in HeD3 Line.